Patent Document 1 discloses an exciter in which a piezoelectric element is accommodated in a case. In Patent Document 1, the exciter is attached to a cowl of a motorcycle, for example. Vibration from the exciter is transmitted to the cowl and makes the cowl vibrate as a vibration plate to generate a sound. The piezoelectric vibration unit is attached to a panel of a mobile phone, for example, and makes the panel vibrate as a vibration panel to generate a sound.